Device for comparing sounds.



m haoamm c. M. HECK.

DEVICE FOR COMPARING SOUNDS.

I APPLICATION "LED FEB- 5.195: if LEG-3,329. Patented Oct. 31, 1916.

2 SHEETS-SHEET I- In: "mm-s un: cu. mroumn wanna-nan. n c

C. M. HECK.

DEVICE FOR COMPARING SOUNDS. APPLICATION FILED FEB. s. 1915.

Patented Oct. 31, 1916.

2 SHEETS-SHEET 2- UNITED STATES PATENT OFFICE.

DEVICE FOR COMPARING SOUNDS.

Specification of Letters Patent.

Patented Oct. 31, 1916.

Application filed February-5, 1915. Serial No. 6,316.

To all whom it may concern:

Be it known that I, CHALLES M. Hncn, a citizen of the United States,residing at Raleigh, in the county of Wake and State of North Carolina,have invented new and useful Improvements in Devices for ComparingSounds, of which the following is a specification.

This invention relates to the art of sound detection and comparison.

In all observations made by the senses, impressions on the brain rapidlylose their intensity and character, the memory being thus unable tocompare sensations following'each other at relatively long intervals. Inobservations on light, some hundred fold increase of accuracy has beenattained by utilizing instruments that will place two lights to becompared before the eyes at the same time, or one. light after anotherin rapid succession.

One of the objects of the present invention is to accomplish a similarresult in connection with sound observation, whereby the detection andinvestigation of sounds, the

resonant properties of bodies, and the reflecting and absorbingquantities, may be more accurately conducted than has heretofore beenpossible.

A further object is to provide for eflicient comparison of sounds byequalizing the vol umes of the sounds being investigated, leaving thenature or character'of the sounds undisturbed.

A further-object is to provide means whereby resonance properties ofcavities may be determined and compared by percussion or impinging ofsound waves.

A further object is to provide means whereby the sound reflectingproperties of surfaces may be determined and compared.

A further object is to provide means for thoroughly insulating theapparatus from extraneous sounds.

The invention will be hereinafter fully set forth and particularlypointed out in the claims.

In the accompanying drawings :-Figure 1 is a view of a stethoscopeconstructed in accordance with my invention. Fig. 2 is an enlargeddetail view illustrating the sound equalizing device. Fig. 3 is an endview thereof. Fig. 4 is a diagrammatic transverse sectional viewthereof. Fig. 5 is an enlargeddetail view of one of the recalled sounddirecting devices, for

ceiving chambers. Fig. 6 is a detail of the locking device. Fig. 7 is adetail view of a slight modification. Fig. 8 is a diagrammatic viewillustrating one of the uses of my invention.

Referring to the drawing, the instrument illustrated in Fig. l is aconvenient form of the doctors stethoscope, although it will appearlater that the instrument is not limited to medical work. Thestethoscope illustrated comprises the ear nipples 10, connected withtubes 11 leading from the arms 12 of a coupling 13. Said coupling isprovided with lower branches 14 from which tubes 15 lead to the cups 16,designed to receive the sound in the well known manner. For convenience,the cups l6, and tubes 15, may be called receiving members, and thetubes 11 and ear pieces 10, delivery members. Said cups 16 may also betechnically the reason that they perform the function of directingsounds received by them.

Rotatably supported by the coupling 13, and preferably by the branches14:, is a valve member 17 provided with openings 18 and 19, arranged atan angle with respect to each other, and located so as to control thepassage rf sound waves through said branches let. The openings 18 and 19are arranged as shown in Fig. 1, it being apparent from said figure thateither tube may be open when the other is closed, or both open to thesame extent at the same time, or one full open and the other open to anydesired fraction. An indicating scale 20 mounted on one of the tubes 11,acting also as a cap to hold the valve member 17 in position, isprovided, said cap being attached in suit able manner. The end of thevalve member is provided with a head 22 having a pointer 23 cooperatingwith the scale '20 to indicate the adjustment of the valve. By the useof this arrangement, the valve member may be adjusted so that the volumeof sound pass ing from branches 11 to the arms 12 will be equalized,rendering it possible to determine the nature of the respective soundswithout regard to any difference in volume at the source. Thus twosounds of ditierent volumes may be equalized as to the volume byadjusting the valve member so that the openings 18 and 19 will equalizeany dif ference in the volume.

The receiving cup or mouth piece 16 may M my? shutter or diaphragm 26 isprovided with a milled head 27 bv which itmay be ro-- tated, but isnormally held in its closed position against shoulders 28 by means of aspring :29. 'hen the shutter is opened and released the spring 29 causesthe same to fly back to shut position. To .preventa noise as the shutteris closed, an insulated stop 30 is placed outside of the chamber '24 toengage the head 27, and thereby limit the movement of said shutter.Should itbe desired to lock the shutter in open position, a spring latch3.1. is provided having a finger adapted to engage an opening 32 in thehead 52?.-

The mouth piece is detachably connected to the shutter chamber 24, inany suitable manner, as the threaded portion 33. For ordinary soundobservation in connection with the usual medical use of a stethoscope,the cups may be of the usual type. For percussion testing however, a cupis employed in which is secured a leaf spring 35 to which is. secured asuitable hammer 36, said spring being held in position by a suitablesound insulated clamp 37. PIOJQCtlIlg through an opening in the wall ofthe cup is a ratchet wheel 38 rotatably supported by a leaf spring 39,which is also supported by a sound insulated clamp. The insulationcomprises spaced apart felt-washers' connected b v an intermediate felttube through which the bolt of the clamp passes. A suitable cover 41 maybe provided for the ratchet wheel, in order to enable the cup to be usedin the ordinary manner, if the percussion device is not to be utilizedat any specific time.

, In operation, the open end-of the cup is placed upon the surfaceof-the body to be tested. and the hand holding the mouth piece has onefinger on the ratchet and by rotating the latter the teeth thereofsuccessively. engage the leaf spring and thus make a stroke with thehammer 36. Each time that the leaf spring is released by the ratchet,the hammer 36 will strike against the surface with which the cup is incontact, and the character of the sound emitted by said surface, whenstruck by the hammer will, of course, vary with the nature of the bodybeing tested. To increase the intensity of the stroke, the finger whilepushing the teeth forward presses the ratchet wheel inwardly, thuselevating the spring 35 a greater distance before its release. Duringthe foregoing operation the ing device -ll constructed to support awatch 42. or other similar sound producing device.

The watch is thoroughly insulated against transmission of sound to' thewall of the cup by means of suitable packing 43, of felt or similarmaterial. The reflector is best used with a wall 44, one side of whichhas a felt damper 45, said wall being so shaped as to protect theshutter chamber from sounds that may come without first reflectingagainst the object 46, on which the mouth of the cup is placed.

All of the cups, shutter chambers, and other parts arepreferablyprovided with an insulating covering, best illustrated in Fig.7, so as to protect the parts of the instru ment from extraneous soundssuch as produced by rubbing or striking the harder partsof theapparatus. Said insulation comprises anelastic covering 47 such as sheetrubber. inclosing a loose sound absorbing felt 4S.

It will be understood that while thereceiving cups and their attachmentsand adjuncts have been illustrated and described in connection with adouble stethoscope, I do not desire to limit myself in this particular.as it is obvious that the same may be applied to any of the well knownforms of stethoscope'withoutdeparting from the spirit of my invention.

In Fig. 81 have illustrated a methodof comparing the diaphragms of soundreproducing machines to determine differences in qualityand character ofsound reproduction. Referring to said figure, 50 and 51 indicateconventionally.illustrated graphephones. provided with the usualdiaphragms supported in suitable manner as indicated at 52 and 53. Thesound receiving cups or members 54: are connected with the dia phragmsupports 52, 53 and are provided with sound excluding shutters 55. Saidreceiving cups or members are connected by tubes 56 with the branches 57of a coupling member 58, and a sound equalizing device 59 is preferablyprovided. The upper branches 60 of the coupling member are connected bytubes 61 with the delivery members 62 which are also provided with soundexcluding shutters 63. Said delivery members perform the function ofsound directing devices. The shutters 55 and 63 are similar inconstruction to shutters 26, and

are provided with similar adjuncts. In operation, the machines and 51are operated simultaneously and the sound reproduced by each will bedelivered through members 62, the shutters 63 being locked in openposition. By adjusting member 59 to equalize the volumes of sound, theoperator by alternately operating the shutters may accurately comparethe work of the two diaphragms 52, 53. If it is desired to make acomparative test of amplifying devices, they are made to perform thefunctions of cle-v livery members 62, one of the shutters 55 beinglocked in open position. By alternately operating the shutters 63 anydifferences in the two amplifying devices may be readily determined.

Having thus explained the nature of my invention and described anoperative manner of constructing and using the same, although withoutattempting to set forth all of the forms in which it may be made, or allof the forms of its use, what I claim is 1. A device of the characterdescribed comprising a coupling member, means for directing sounds fromdifferent sources to said coupling member, sound delivering membersleading from said coupling member, and means for varying the relativevolumes of the sounds passing through said coupling member to saiddelivering member to equalize the same; 7

2. A device of. the character described comprising a coupling member,means for directing sounds from different sources to said couplingmember, sound delivering members connected to said coupling member, andmeans for controlling the passage of sounds from the coupling memberto'the delivering members.

3. A device of the character described comprising a coupling member,means for directing sounds from different sources to said couplingmember, sound delivering members connected to said coupling member, andmeans for controlling the passage of sounds from the receiving membersto the coupling member.

4. A device of the character described comprising a coupling member,sound delivery members connected to said coupling member to deliversounds thereto, a plurality of sound receiving members leading from saidcoupling member, and a rotatable valve provided with means forequalizing the volumes of the sounds passing from said receiving membersto said delivering members.

5. A device of the character described comprising a coupling providedwith branches, sound delivering members con nected with said coupling, aplurality of sound receiving members connected with said branches, andmeans cooperating with said branches for equalizing the volumes of thesounds passing from said receiving members through said branches.

6. 1 device of the character described comprising a coupling memberprovided with branches, sound delivering members connected to saidcoupling member, a plurality of sound receiving members connected withsaid b 'anches, and a valve member rotatably supported by said branchesand provided with means for equalizing the volumes of the sounds passingthrough said branches. I

7. A device of the character described comprising a coupling member,sound delivering members connected thereto, a plurality of soundreceiving members also connected with said coupling members, a rotatablevalve provided with openings controlling the passage of sounds from saidreceiving members to said delivering members, said openings beingarranged at an angle to each other, and means for indicating theposition of said openings. 7

8. A device of the character described comprising a coupling memberprovided with branches, sound delivering members connected with saidcoupling member, sound receiving members connected with said branches, arotatable valve member sup-. ported by said branches and provided withopenings controlling the assage of sounds through said branches, saidopenings being arranged at an angle toeach other, and means forindicating the positions of said openings relative to the bores of thebranches.

9. A device of the character described comprising a sound receivingmember adapted to rest against an object to be tested, and a soundproducing device located within said chamber and cooperating with thesurface of said object.

10. A device of the character described comprising a sound receivingmember adapted to rest against an object to be tested, and a percussiondevice located within said member and cooperating with the sur face ofsaid object.

11. A device of the character described comprising a sound receivingmember adapted to rest against an object to be tested, a percussiondevice located within said member and cooperating with the surface ofsaid object, and means carried by the cup for operating said percussiondevice. 12. A device of the character described comprising a soundreceiving member adapted to rest against. an obiect to be tested aresilient percussion member located within said member and coiiperatingwith the surface of said object, and means for variably operating saidpercussion member.

13. A device of the character described comprising a sound receivingmember adapted to rest against an object to be tested, a

having one end secured to the wall of the latter, and means supported bysaid receiving member for engaging the free end of said resilient arm toimpart movement'to the latter, whereby the same will strike the surfaceof said object.

15. A device of the character described comprising a sound receivingmember adapted to rest against an object to be tested,a resilientpercussion member located within said receiving member and cooperatingwith the surface of said object, and a ratchet wheel engagingsaid'resilient member.

16. A device of the character described comprising a sound receivingmember, a resilient percussion member located within said receivingmember, a ratchet wheel engaging said resilieiitmember, and means foryield'ingly supporting said ratchet wheel;

17.- A device of the character described comprising a sound receivingmember, a

percussion member located within said receiving member, a ratchet wheelengaging said resilient member, *and a resilient "arm" secured to saidcup and supporting said ratchetwheel.

18'. 1 device of the character described comprising a sound receivingmember having an opening in its wall, a 'atchet wheel support-ed withinsaid receiving member and extending through said opening, and apercussion device within said receiving member and operated by said-atchet wheel.

19. A' device of the character described comprising a sound receivingmember hav-' ing an opening in one wall, a ratchet wheel supportedwithin said receiving member and extending through said opening, apercussion device within said receiving member and operated by saidratchet wheel, and a cover for said ratchet wheel and said'opening toprevent escape of sounds when the percussion device is not in use.

20. A sound comparing device comprising a coupling member provided witha main sound passage and branches communicating therewith, sounddirect-ing devices communieating with said branches, each sounddirecting device being independently movable in any direction, andseparate means controlling the respective branches to selectivelyinterrupt the travel of sounds therethrouglu 21. A sound comparingdevice comprising a coupling member provided with a plurality of soundpassages and sound receiving members communicating with said passages,each of said receiving members being independently movable in anydirection, and means for selectively interrupting the passage of soundsthrough said passages.

22. A sound comparing device comprising a. coupling member provided witha plurality of sound passages and sound receiving members communicatingwith said passages,

each of said receiving members being indesages and having means foropening one passage and simultaneously closing the other in proportion,and means for indicating the extent of the relative openings of saidpassages efl'ected bymovem'ent of the valves.

In a sound comparing device, a coupling member provided-with airpassages, I

means connected with said air passages for receiving sounds found atdifferent points, a valve provided with *angularlydisposed openingscontrolling said passages, the relative angle of the openings being.such that as one air passage is opened the other is closed in proportionthereto.

26. A device of the character described comprising a coupling member,means for directing sounds from diiferent sources to said couplingmember, sound delivering members leading from said coupling member,means for varying the relative volumes of the sounds passing throughsaid coupling member to said delive'ringmembers to equalize the same,and a valve member controlling said passages andhaving means for openingone passage and simultaneously closing the other in proportion.

27. A device of the character described comprising a sound receivingmember adapted to rest against an object to be tested, a soundpercussion device located within said member and cooperating with thesurface of said object, an operating device for saidpercussion device,and means whereby the intensity of the stroke of" said percussion may bevaried.

28. A device of the character described, comprising a sound receivingmember adapted to rest against an object to be tested, a percussiondevice located Within said member and cooperating with the surface ofsaid object, a device for operating 130.

said percussion device, and a resilient support for said operatingdevice.

29. Asound comparing device comprising means for simultaneouslyreceiving sounds at different points, means for directing the receivedsounds through different paths to a common-point of observation, andmeans for successively controlling the passage of sounds from saidreceiving points to their respective path directing means.

' 30. In a sound controlling device, the combination with an amplifyingdevice having a cavity adapted to be placed over and closed by asurface, and means located within the cavity for producing soundsvarying with the nature of said surface.

31. A stethoscope comprising two separate transmitters, tubes securedthereto adapted toconvey sound therefrom, means for preventing thepassage of sound through said tubes, a chamber connected with saidtubes, ear pieces, and tubes connecting the latter with said chamber.

32. A device of the character described comprising a sound receivingmember having edges shaped to rest upon a surface, said member having asingle outlet port, a sound conduit attached to said receiving memberconcentrically with respect to said outlet port to receive sounddirectly therefrom, a valve controlling passage of sound through saidoutlet port, and means for yieldingly holding said valve in a normallypredeter- V mined position.

In testimony whereof I have hereunto se my hand 1n presence of twosubscribmg witnesses.

CHARLES M. HEGK.

Copies of this patent may be obtained for five cents each, by addressingthe "Commissioner of Patents,

n Washington, D. O.

